Pituitary Hyperplasia Secondary to Prolonged Undiagnosed Hypothyroidism in a 13-Year-Old Female

Abstract

Background

Pituitary hyperplasia is often overlooked as a potential complication of chronic hypothyroidism. When hypothyroidism persists, the disruption of the negative feedback loop from the thyroid can lead to increased thyrotropin production in the pituitary, resulting in hyperplasia.

Objective

This case report aims to explore pituitary hyperplasia as a reversible complication of untreated primary hypothyroidism, highlighting the importance of timely diagnosis and appropriate treatment to prevent unnecessary interventions.

Case Description

We reported a 13-year-old female presented with psychosis, crying spells, and emotional instability, which led to an initial psychiatric evaluation. Laboratory tests revealed severely elevated thyroid-stimulating hormone (TSH) levels greater than 100 mIU/L, low free thyroxine (T4) levels at 0.1 ng/dL, and high thyroid peroxidase antibodies (> 600 IU/mL), confirming a diagnosis of Hashimoto's thyroiditis and severe primary hypothyroidism. A pituitary magnetic resonance imaging showed signs of pituitary hyperplasia. Following the initiation of levothyroxine therapy, the patient's TSH levels normalized, and the pituitary hyperplasia significantly regressed. The patient has since remained stable and asymptomatic.

Conclusion

This case report details a 13-year-old female diagnosed with Hashimoto's thyroiditis and pituitary hyperplasia. Following levothyroxine treatment, both thyroid function and pituitary size normalized, leading to significant clinical improvement. This case highlights the importance of recognizing pituitary hyperplasia as a reversible condition caused by hypothyroidism. It underscores the critical need for timely diagnosis and appropriate treatment to prevent unnecessary surgical interventions.

Keywords

pituitary hyperplasia - hypothyroidism - Hashimoto's thyroiditis - thyroid-related pituitary disorders - psychiatric manifestations of hypothyroidism

Authors' Contributions

S.M.AK.H contributed to case management and follow-up, manuscript drafting, critical review, literature review, manuscript editing, and final approval of the manuscript. A.A.M. was responsible for case diagnosis and management, figure preparation, supervision, manuscript revision, and final approval of the manuscript.

Compliance with Ethical Principles

This case report was reviewed and approved by the Institutional Review Board of Faiha Specialized Diabetes, Endocrine and Metabolism Center (FDEMC).

Patient's Consent

Written informed consent was obtained from the patient's father for the publication of this case report.

Publication History

Article published online:
01 May 2025

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